There are many situations in which a control panel would need to be accessible from both inside and outside an enclosed space. One such situation may arise in enclosed spaces where the temperature, humidity, or other environmental parameters are under strict control, such as cleanrooms, art preservation enclosures, high-oxygen enclosures for medical use, steamrooms, or saunas. In such situations, a user may not want to have to enter the enclosed space in order to access the controls on the inside, or, once inside, to have to exit the enclosed space in order to access the controls on the outside. While it is possible to design such an enclosed space to have two sets of controls, one on the inside and one on the outside, it is expensive and unnecessarily duplicative.
This problem is especially applicable to saunas, since once a user is relaxing inside a sauna, he or she may not want to have to exit the sauna in order to change the temperature; on the other hand, if a user wants to set the temperature in a sauna ahead of time, he or she may not want to enter the sauna wearing shoes and regular street clothes.
It may also be unsafe to have a sauna where the temperature is only controllable from the outside. If the door to the sauna gets stuck or jammed, and the user is unable to exit the sauna, he or she has no way to turn off the heating unit.
One solution to the problem, as it pertains to saunas, is described in U.S. Pat. No. 4,384,190 to Janson. Janson discloses a control panel arrangement for a sauna heating unit that can be operated from either inside or outside the sauna; it comprises a temperature control knob and an on-off switch on the outside of the sauna that are connected to shafts going through a special air channel into the inside of the sauna, enabling the user to control the temperature knob or the on-off switch from inside the sauna as well. While this invention solves the problem, it is complex and cumbersome.
Modern touchscreen panels are much easier and more convenient to use than control knobs, and some sauna designs do incorporate touchscreen control panels. However, most such saunas only offer one touchscreen control panel on the outside of the sauna, or two touchscreens, one on the inside and one on the outside. The first is unsafe and inconvenient for the user, and the second is expensive and unnecessarily complex.
A need therefore exists for a way to control an enclosed space with one control panel that can be accessed from either inside or outside the space.